Caries / holes
Caries or tooth decay (holes) are the most common infectious disease in the world. It is estimated that 95% of the world’s population is affected.
What is it?
Caries are the result of a demineralisation process involving the dental tissue: tooth enamel, dentine (dental bone) and root cementum. Demineralisation is initiated by acids secreted by certain bacteria after being converted from sugars. The most common bacteria types that cause caries are streptococcus mutans and lactobacillus. Due to the secretion of acids by these bacteria, the pH drops and saliva becomes acidic. Acidity increases the solubility of calcium hydroxyapatite (the mineral from which enamel is made) and dissolves it. This creates a cavity, a hole.
Foods high in acid cause direct demineralisation, the results of which is not called caries, but dental erosion. The bacteria that cause caries can be found everywhere in the mouth. Everyone has these bacteria in his mouth, to a greater or lesser degree. These bacteria can be found in dental plaque. It is via dental plaque that these bacteria cause caries.
Dental plaque contains:
- bacteria and the acids that they secrete
- chemicals, mainly proteins, from saliva
- leftover food and drink.
- minerals from dissolved pieces of teeth and from toothpaste, saliva, etc.
If this plaque remains on the tooth surface for a long time, and the patient’s immunity is low, for example, caries will begin to form. Dentists recommend the use of dental floss (or a toothpick or interdental brush) after eating, to remove as much of this plaque as possible.
The first sign of an affected tooth or molar is usually seen as a white dull spot (lesion) on the enamel, which can diminish as time passes. Up to this point, a tooth can still be saved through remineralisation. A lesion (the start of a hole) that heals can be recognised by the presence of hard and shiny discoloration (white or brown).
As the process continues, the enamel softens and crumbles and a cavity develops. This creates a hole which allows bacteria to gain access to the dentine. The dentine is partly composed of organic material which the bacteria consume, rendering the tooth rotten. Teeth have a defence mechanism (they close the dentinal canals), but where long-term and frequent acid attacks are involved (due to regular sugar consumption), this is insufficient. Caries can then reach the tooth nerve and cause irritation, accompanied by toothache.
This is precisely why we think that the six-monthly check-up is so important. This means we can intervene at an as early stage as possible. In cases of inadequate oral hygiene, it may be necessary to visit a dental prevention assistant who can help you to improve your teeth-cleaning technique and method.
A useful tool for early diagnosis of caries is the so-called “bitewings”. These are x-ray pictures of your teeth as they bite down. These show us both the lower and upper teeth on either side of your jaw. Early stage caries can be seen, meaning a filling can remain small. Without this x-ray, these would be missed.
What we do
At our practice we mainly produce white fillings. In exceptional cases, after consultation, amalgam is still used to fill holes in the teeth. In the field of dentistry, composites are used – a filler material consisting of a matrix phase and a filler phase. In practice, this is a filler material with a matrix of synthetic resin, a binder and inorganic filler such as quartz or glass. The filler adds strength, the synthetic resin means the material is pliable when placing the filling, and the binder (silane) bonds these materials together.
Unlike amalgam, which stays in place through pressure, composites, after the tooth has been roughened with a 35 to 50% solution of phosphoric (or alternative) acid and a primer and a bonder applied, is glued to the dental tissue. Composites can be obtained with chemical or light hardening properties. A combination of the two is also possible: these are the so-called dual-cure composites. The polymerisation process is initiated either with chemicals or light (photopolymerisation). With chemical hardening composites, two pastes are often mixed. Light-cured composites become hard because the product combines camphorchinone into radicals that begin the polymerisation process.
Because composites are not immune to shrinkage, it is very important to minimise the chance of this happening as much as possible. The dentist can do this by not filling the cavity all at once, especially if it is large. By applying the composite in layers, total shrinkage can be compensated and the chance that all of these layers are completely cured is much higher. The maximum curing thickness for the majority of curing lamps is about 3 mm. The layering of composites mean that so-called “white filling sensitivity” is minimal.